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<h1><img src="../../../../boost.png" align="middle" />Vector Proxies</h1>
<div class="toc" id="toc"></div>
<h2><a name="vector_range"></a>Vector Range</h2>
<h4>Description</h4>
<p>The templated class <code>vector_range&lt;V&gt;</code> allows
addressing a sub-range of a vector's element.</p>
<h4>Example</h4>
<pre>
#include &lt;boost/numeric/ublas/vector.hpp&gt;
#include &lt;boost/numeric/ublas/vector_proxy.hpp&gt;
#include &lt;boost/numeric/ublas/io.hpp&gt;

int main () {
    using namespace boost::numeric::ublas;
    vector&lt;double&gt; v (3);
    vector_range&lt;vector&lt;double&gt; &gt; vr (v, range (0, 3));
    for (unsigned i = 0; i &lt; vr.size (); ++ i)
        vr (i) = i;
    std::cout &lt;&lt; vr &lt;&lt; std::endl;
}
</pre>
<h4>Definition</h4>
<p>Defined in the header vector_proxy.hpp.</p>
<h4>Template parameters</h4>
<table border="1" summary="parameters">
<tbody>
<tr>
<th>Parameter</th>
<th>Description</th>
<th>Default</th>
</tr>
<tr>
<td><code>V</code></td>
<td>The type of vector referenced.</td>
<td></td>
</tr>
</tbody>
</table>
<h4>Model of</h4>
<p><a href="expression_concept.html#vector_expression">Vector Expression</a>
.</p>
<p>If the specified range falls outside that of the index range of
the vector, then the <code>vector_range</code> is not a well formed
Vector Expression. That is, access to an element which is outside
of index range of the vector is <i>undefined</i>.</p>
<h4>Type requirements</h4>
<p>None, except for those imposed by the requirements of <a href=
"expression_concept.html#vector_expression">Vector Expression</a> .</p>
<h4>Public base classes</h4>
<p><code>vector_expression&lt;vector_range&lt;V&gt; &gt;</code></p>
<h4>Members</h4>
<table border="1" summary="members">
<tbody>
<tr>
<th>Member</th>
<th>Description</th>
</tr>
<tr>
<td><code>vector_range (vector_type &amp;data, const range
&amp;r)</code></td>
<td>Constructs a sub vector.</td>
</tr>
<tr>
<td><code>size_type start () const</code></td>
<td>Returns the start of the sub vector.</td>
</tr>
<tr>
<td><code>size_type size () const</code></td>
<td>Returns the size of the sub vector.</td>
</tr>
<tr>
<td><code>const_reference operator () (size_type i)
const</code></td>
<td>Returns the value of the <code>i</code>-th element.</td>
</tr>
<tr>
<td><code>reference operator () (size_type i)</code></td>
<td>Returns a reference of the <code>i</code>-th element.</td>
</tr>
<tr>
<td><code>const_reference operator [] (size_type i)
const</code></td>
<td>Returns the value of the <code>i</code>-th element.</td>
</tr>
<tr>
<td><code>reference operator [] (size_type i)</code></td>
<td>Returns a reference of the <code>i</code>-th element.</td>
</tr>
<tr>
<td><code>vector_range &amp;operator = (const vector_range
&amp;vr)</code></td>
<td>The assignment operator.</td>
</tr>
<tr>
<td><code>vector_range &amp;assign_temporary (vector_range
&amp;vr)</code></td>
<td>Assigns a temporary. May change the vector range
<code>vr</code> .</td>
</tr>
<tr>
<td><code>template&lt;class AE&gt;<br />
vector_range &amp;operator = (const vector_expression&lt;AE&gt;
&amp;ae)</code></td>
<td>The extended assignment operator.</td>
</tr>
<tr>
<td><code>template&lt;class AE&gt;<br />
vector_range &amp;assign (const vector_expression&lt;AE&gt;
&amp;ae)</code></td>
<td>Assigns a vector expression to the sub vector. Left and right
hand side of the assignment should be independent.</td>
</tr>
<tr>
<td><code>template&lt;class AE&gt;<br />
vector_range &amp;operator += (const vector_expression&lt;AE&gt;
&amp;ae)</code></td>
<td>A computed assignment operator. Adds the vector expression to
the sub vector.</td>
</tr>
<tr>
<td><code>template&lt;class AE&gt;<br />
vector_range &amp;plus_assign (const vector_expression&lt;AE&gt;
&amp;ae)</code></td>
<td>Adds a vector expression to the sub vector. Left and right hand
side of the assignment should be independent.</td>
</tr>
<tr>
<td><code>template&lt;class AE&gt;<br />
vector_range &amp;operator -= (const vector_expression&lt;AE&gt;
&amp;ae)</code></td>
<td>A computed assignment operator. Subtracts the vector expression
from the sub vector.</td>
</tr>
<tr>
<td><code>template&lt;class AE&gt;<br />
vector_range &amp;minus_assign (const vector_expression&lt;AE&gt;
&amp;ae)</code></td>
<td>Subtracts a vector expression from the sub vector. Left and
right hand side of the assignment should be independent.</td>
</tr>
<tr>
<td><code>template&lt;class AT&gt;<br />
vector_range &amp;operator *= (const AT &amp;at)</code></td>
<td>A computed assignment operator. Multiplies the sub vector with
a scalar.</td>
</tr>
<tr>
<td><code>template&lt;class AT&gt;<br />
vector_range &amp;operator /= (const AT &amp;at)</code></td>
<td>A computed assignment operator. Divides the sub vector through
a scalar.</td>
</tr>
<tr>
<td><code>void swap (vector_range &amp;vr)</code></td>
<td>Swaps the contents of the sub vectors.</td>
</tr>
<tr>
<td><code>const_iterator begin () const</code></td>
<td>Returns a <code>const_iterator</code> pointing to the beginning
of the <code>vector_range</code>.</td>
</tr>
<tr>
<td><code>const_iterator end () const</code></td>
<td>Returns a <code>const_iterator</code> pointing to the end of
the <code>vector_range</code>.</td>
</tr>
<tr>
<td><code>iterator begin ()</code></td>
<td>Returns a <code>iterator</code> pointing to the beginning of
the <code>vector_range</code>.</td>
</tr>
<tr>
<td><code>iterator end ()</code></td>
<td>Returns a <code>iterator</code> pointing to the end of the
<code>vector_range</code>.</td>
</tr>
<tr>
<td><code>const_reverse_iterator rbegin () const</code></td>
<td>Returns a <code>const_reverse_iterator</code> pointing to the
beginning of the reversed <code>vector_range</code>.</td>
</tr>
<tr>
<td><code>const_reverse_iterator rend () const</code></td>
<td>Returns a <code>const_reverse_iterator</code> pointing to the
end of the reversed <code>vector_range</code>.</td>
</tr>
<tr>
<td><code>reverse_iterator rbegin ()</code></td>
<td>Returns a <code>reverse_iterator</code> pointing to the
beginning of the reversed <code>vector_range</code>.</td>
</tr>
<tr>
<td><code>reverse_iterator rend ()</code></td>
<td>Returns a <code>reverse_iterator</code> pointing to the end of
the reversed <code>vector_range</code>.</td>
</tr>
</tbody>
</table>
<h3>Simple Projections</h3>
<h4>Description</h4>
<p>The free <code>subrange</code> functions support the construction
of vector ranges.</p>
<h4>Prototypes</h4>
<pre><code>
    template&lt;class V&gt;
    vector_range&lt;V&gt; subrange (V &amp;data,
       V::size_type start, V::size_type stop);
    template&lt;class V&gt;
    const vector_range&lt;const V&gt; subrange (const V &amp;data,
       V::size_type start, V::size_type stop);
</code></pre>
<h3>Generic Projections</h3>
<h4>Description</h4>
<p>The free <code>project</code> functions support the construction
of vector ranges. Existing <code>matrix_range</code>'s can be composed with a further range. The resulting range is computed using this existing range's <code>compose</code> function.</p>
<h4>Prototypes</h4>
<pre><code>
    template&lt;class V&gt;
    vector_range&lt;V&gt; project (V &amp;data, const range &amp;r);
    template&lt;class V&gt;
    const vector_range&lt;const V&gt; project (const V &amp;data, const range &amp;r);
    template&lt;class V&gt;
    vector_range&lt;V&gt; project (vector_range&lt;V&gt; &amp;data, const range &amp;r);
    template&lt;class V&gt;
    const vector_range&lt;V&gt; project (const vector_range&lt;V&gt; &amp;data, const range &amp;r);
</code></pre>
<h4>Definition</h4>
<p>Defined in the header vector_proxy.hpp.</p>
<h4>Type requirements</h4>
<ul>
<li><code>V</code> is a model of <a href=
"expression_concept.html#vector_expression">Vector Expression</a> .</li>
</ul>
<h4>Complexity</h4>
<p>Linear depending from the size of the range.</p>
<h4>Examples</h4>
<pre>
#include &lt;boost/numeric/ublas/vector.hpp&gt;
#include &lt;boost/numeric/ublas/vector_proxy.hpp&gt;
#include &lt;boost/numeric/ublas/io.hpp&gt;

int main () {
    using namespace boost::numeric::ublas;
    vector&lt;double&gt; v (3);
    for (int i = 0; i &lt; 3; ++ i)
        project (v, range (0, 3)) (i) = i;
    std::cout &lt;&lt; project (v, range (0, 3)) &lt;&lt; std::endl;
}
</pre>
<h2><a name="vector_slice"></a>Vector Slice</h2>
<h4>Description</h4>
<p>The templated class <code>vector_slice&lt;V&gt;</code> allows
addressing a slice of a vector.</p>
<h4>Example</h4>
<pre>
#include &lt;boost/numeric/ublas/vector.hpp&gt;
#include &lt;boost/numeric/ublas/vector_proxy.hpp&gt;
#include &lt;boost/numeric/ublas/io.hpp&gt;

int main () {
    using namespace boost::numeric::ublas;
    vector&lt;double&gt; v (3);
    vector_slice&lt;vector&lt;double&gt; &gt; vs (v, slice (0, 1, 3));
    for (unsigned i = 0; i &lt; vs.size (); ++ i)
        vs (i) = i;
    std::cout &lt;&lt; vs &lt;&lt; std::endl;
}
</pre>
<h4>Definition</h4>
<p>Defined in the header vector_proxy.hpp.</p>
<h4>Template parameters</h4>
<table border="1" summary="parameters">
<tbody>
<tr>
<th>Parameter</th>
<th>Description</th>
<th>Default</th>
</tr>
<tr>
<td><code>V</code></td>
<td>The type of vector referenced.</td>
<td></td>
</tr>
</tbody>
</table>
<h4>Model of</h4>
<p><a href="expression_concept.html#vector_expression">Vector Expression</a>
.</p>
<p>If the specified slice falls outside that of the index range of
the vector, then the <code>vector_slice</code> is not a well formed
Vector Expression. That is, access to an element which is outside
of index range of the vector is <i>undefined</i>.</p>
<h4>Type requirements</h4>
<p>None, except for those imposed by the requirements of <a href=
"expression_concept.html#vector_expression">Vector Expression</a> .</p>
<h4>Public base classes</h4>
<p><code>vector_expression&lt;vector_slice&lt;V&gt; &gt;</code></p>
<h4>Members</h4>
<table border="1" summary="members">
<tbody>
<tr>
<th>Member</th>
<th>Description</th>
</tr>
<tr>
<td><code>vector_slice (vector_type &amp;data, const slice
&amp;s)</code></td>
<td>Constructs a sub vector.</td>
</tr>
<tr>
<td><code>size_type size () const</code></td>
<td>Returns the size of the sub vector.</td>
</tr>
<tr>
<td><code>const_reference operator () (size_type i)
const</code></td>
<td>Returns the value of the <code>i</code>-th element.</td>
</tr>
<tr>
<td><code>reference operator () (size_type i)</code></td>
<td>Returns a reference of the <code>i</code>-th element.</td>
</tr>
<tr>
<td><code>const_reference operator [] (size_type i)
const</code></td>
<td>Returns the value of the <code>i</code>-th element.</td>
</tr>
<tr>
<td><code>reference operator [] (size_type i)</code></td>
<td>Returns a reference of the <code>i</code>-th element.</td>
</tr>
<tr>
<td><code>vector_slice &amp;operator = (const vector_slice
&amp;vs)</code></td>
<td>The assignment operator.</td>
</tr>
<tr>
<td><code>vector_slice &amp;assign_temporary (vector_slice
&amp;vs)</code></td>
<td>Assigns a temporary. May change the vector slice
<code>vs</code> .</td>
</tr>
<tr>
<td><code>template&lt;class AE&gt;<br />
vector_slice &amp;operator = (const vector_expression&lt;AE&gt;
&amp;ae)</code></td>
<td>The extended assignment operator.</td>
</tr>
<tr>
<td><code>template&lt;class AE&gt;<br />
vector_slice &amp;assign (const vector_expression&lt;AE&gt;
&amp;ae)</code></td>
<td>Assigns a vector expression to the sub vector. Left and right
hand side of the assignment should be independent.</td>
</tr>
<tr>
<td><code>template&lt;class AE&gt;<br />
vector_slice &amp;operator += (const vector_expression&lt;AE&gt;
&amp;ae)</code></td>
<td>A computed assignment operator. Adds the vector expression to
the sub vector.</td>
</tr>
<tr>
<td><code>template&lt;class AE&gt;<br />
vector_slice &amp;plus_assign (const vector_expression&lt;AE&gt;
&amp;ae)</code></td>
<td>Adds a vector expression to the sub vector. Left and right hand
side of the assignment should be independent.</td>
</tr>
<tr>
<td><code>template&lt;class AE&gt;<br />
vector_slice &amp;operator -= (const vector_expression&lt;AE&gt;
&amp;ae)</code></td>
<td>A computed assignment operator. Subtracts the vector expression
from the sub vector.</td>
</tr>
<tr>
<td><code>template&lt;class AE&gt;<br />
vector_slice &amp;minus_assign (const vector_expression&lt;AE&gt;
&amp;ae)</code></td>
<td>Subtracts a vector expression from the sub vector. Left and
right hand side of the assignment should be independent.</td>
</tr>
<tr>
<td><code>template&lt;class AT&gt;<br />
vector_slice &amp;operator *= (const AT &amp;at)</code></td>
<td>A computed assignment operator. Multiplies the sub vector with
a scalar.</td>
</tr>
<tr>
<td><code>template&lt;class AT&gt;<br />
vector_slice &amp;operator /= (const AT &amp;at)</code></td>
<td>A computed assignment operator. Divides the sub vector through
a scalar.</td>
</tr>
<tr>
<td><code>void swap (vector_slice &amp;vs)</code></td>
<td>Swaps the contents of the sub vectors.</td>
</tr>
<tr>
<td><code>const_iterator begin () const</code></td>
<td>Returns a <code>const_iterator</code> pointing to the beginning
of the <code>vector_slice</code>.</td>
</tr>
<tr>
<td><code>const_iterator end () const</code></td>
<td>Returns a <code>const_iterator</code> pointing to the end of
the <code>vector_slice</code>.</td>
</tr>
<tr>
<td><code>iterator begin ()</code></td>
<td>Returns a <code>iterator</code> pointing to the beginning of
the <code>vector_slice</code>.</td>
</tr>
<tr>
<td><code>iterator end ()</code></td>
<td>Returns a <code>iterator</code> pointing to the end of the
<code>vector_slice</code>.</td>
</tr>
<tr>
<td><code>const_reverse_iterator rbegin () const</code></td>
<td>Returns a <code>const_reverse_iterator</code> pointing to the
beginning of the reversed <code>vector_slice</code>.</td>
</tr>
<tr>
<td><code>const_reverse_iterator rend () const</code></td>
<td>Returns a <code>const_reverse_iterator</code> pointing to the
end of the reversed <code>vector_slice</code>.</td>
</tr>
<tr>
<td><code>reverse_iterator rbegin ()</code></td>
<td>Returns a <code>reverse_iterator</code> pointing to the
beginning of the reversed <code>vector_slice</code>.</td>
</tr>
<tr>
<td><code>reverse_iterator rend ()</code></td>
<td>Returns a <code>reverse_iterator</code> pointing to the end of
the reversed <code>vector_slice</code>.</td>
</tr>
</tbody>
</table>
<h3>Simple Projections</h3>
<h4>Description</h4>
<p>The free <code>subslice</code> functions support the construction
of vector slices.</p>
<h4>Prototypes</h4>
<pre><code>
    template&lt;class V&gt;
    vector_slice&lt;V&gt; subslice (V &amp;data,
       V::size_type start, V::difference_type stride, V::size_type size);
    template&lt;class V&gt;
    const vector_slice&lt;const V&gt; subslice (const V &amp;data,
       V::size_type start, V::difference_type stride, V::size_type size);
</code></pre>
<h3>Generic Projections</h3>
<h4>Description</h4>
<p>The free <code>project</code> functions support the construction
of vector slices. Existing <code>vector_slice</code>'s can be composed with a further range or slices. The resulting slice is computed using this existing slices's <code>compose</code> function.</p>
<h4>Prototypes</h4>
<pre><code>
    template&lt;class V&gt;
    vector_slice&lt;V&gt; project (V &amp;data, const slice &amp;s);
    template&lt;class V&gt;
    const vector_slice&lt;const V&gt; project (const V &amp;data, const slice &amp;s);
    template&lt;class V&gt;
    vector_slice&lt;V&gt; project (vector_slice&lt;V&gt; &amp;data, const range &amp;r);
    template&lt;class V&gt;
    const vector_slice&lt;V&gt; project (const vector_slice&lt;V&gt; &amp;data, const range &amp;r);
    template&lt;class V&gt;
    vector_slice&lt;V&gt; project (vector_slice&lt;V&gt; &amp;data, const slice &amp;s);
    template&lt;class V&gt;
    const vector_slice&lt;V&gt; project (const vector_slice&lt;V&gt; &amp;data, const slice &amp;s);
</code></pre>
<h4>Definition</h4>
<p>Defined in the header vector_proxy.hpp.</p>
<h4>Type requirements</h4>
<ul>
<li><code>V</code> is a model of <a href=
"expression_concept.html#vector_expression">Vector Expression</a> .</li>
</ul>
<h4>Complexity</h4>
<p>Linear depending from the size of the slice.</p>
<h4>Examples</h4>
<pre>
#include &lt;boost/numeric/ublas/vector.hpp&gt;
#include &lt;boost/numeric/ublas/vector_proxy.hpp&gt;
#include &lt;boost/numeric/ublas/io.hpp&gt;

int main () {
    using namespace boost::numeric::ublas;
    vector&lt;double&gt; v (3);
    for (int i = 0; i &lt; 3; ++ i)
        project (v, slice (0, 1, 3)) (i) = i;
    std::cout &lt;&lt; project (v, slice (0, 1, 3)) &lt;&lt; std::endl;
}
</pre>
<hr />
<p>Copyright (&copy;) 2000-2002 Joerg Walter, Mathias Koch<br />
   Use, modification and distribution are subject to the
   Boost Software License, Version 1.0.
   (See accompanying file LICENSE_1_0.txt
   or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">
      http://www.boost.org/LICENSE_1_0.txt
   </a>).
</p>
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